The present invention relates to the field of vehicle repair and maintenance, and in particular, relates to a device for the removal of wheels, brake drums, brake rotors, and the like, from a vehicle.
During the repair or maintenance of a vehicle, including trucks, automobiles and the like, it is frequently necessary to remove the wheels, brake rotors and/or brake drums. However, the tolerances between these devices is very small. For example, the clearance between the inner wheel rim and the wheel hub are typically on the order of only several thousands of an inch. Similarly, the clearance between a brake drum or brake rotor and the wheel hub is also very small. Because of these small tolerances and because the wheel hub assembly bears the weight of the vehicle, extended use of the vehicle can frequently cause the inner wheel rim, the brake drum, or the brake rotor, to become essentially fused or seized on the wheel hub.
Once a wheel, for example, is seized on the wheel hub, it can be very difficult to remove the wheel from the vehicle by hand. The common practice in the vehicle repair industry is to have a mechanic hoist the vehicle and hammer on the seized wheel, from the inside, until the wheel becomes loose enough to remove.
This method can, however, cause damage to the rim, the brake drum, the brake rotor, or other parts of the vehicle during hammering. Further, this operation can take an unacceptable amount of time to release the seized part. Yet further, the safety of the mechanic can be jeopardized when hammering a wheel part while under the vehicle.
Still further, if the vehicle should need repair while traveling, such as for example, caused by having a flat tire, it can often be excessively difficult to remove the seized part by hand. Further, hammering of the part with a heavy object is not generally an acceptable option because of the limited space under the vehicle created by lifting the vehicle with a small manual vehicle jack.
In order to address these problems, the prior art provides for a number of different devices to assist in this type of vehicle repair, and to assist in removal of a wheel, a brake rotor, a brake drum, or the like, from a vehicle. These devices may generally be described as xe2x80x9cwheel-pullingxe2x80x9d apparatuses, even though they can also be used for removal of brake drums or brake rotors, in addition to the removal of wheels or wheel rims, from the vehicle.
Some of these known prior art devices are described hereinbelow.
In U.S. Pat. No. 3,402,455 (Converse), issued Apr. 17, 1967, a wheel puller device is described having a central threaded screw which pushes on the hub (or axle) of the vehicle wheel, while two spring-loaded hooks grasp and pull at the rear of the wheel or brake drum to be removed.
In U.S. Pat. No. 3,689,978 (Kelso), issued Sep. 12, 1972, a similar wheel or gear puller device is shown having a central threaded screw which pushes on the hub of the vehicle wheel or gear. Two hooks are attached in the radial grooves of a central yoke or bridge so that the hooks can be moved to be essentially parallel to the central threaded screw during use.
U.S. Pat. No. 4,771,528 (Stromberg), issued Sep. 20, 1988, describes a spindle puller for removal of the front wheel spindle on a four-wheel drive vehicle. Again, the described spindle puller has a central threaded screw which pushes on the axle, while a base plate acts to pull on the spindle. It should be noted that the user is warned not to hammer on the threaded screw, since internal axle parts may be damaged.
U.S. Pat. No. 4,908,925 (Johnson), issued Mar. 20, 1990, describes a wheel hub puller which is used to remove the wheel hub from a axle housing. Again, a central threaded screw acts to push on the axle, while a support frame, bolted to the wheel hub using the wheel lugs (and bolts) acts to pull on the wheel hub.
U.S. Pat. No. 6,012,211 (Ochoa et al.), issued Jan. 11, 2000, describes a wheel puller apparatus having a plate which rests upon the wheel mounting studs, and having two threaded hook portions which extend through the plate and hook onto the rear of the wheel. As bolts are tightened on the threaded hooks, the plate pushes against the wheel mounting studs, while the hooks pull on the wheel rim. The two hooks are alternatively xe2x80x9cpulledxe2x80x9d so that the pushing and pulling forces are first applied on one side of the wheel and then applied on the opposite side of the wheel. This results in a rocking motion which can result in damage to the wheel or brake assembly due to the side-to-side motion of the wheel as it is being freed.
U.S. Pat. No. 6,237,206 (Bezemer et al.), issued May 29, 2001, describes a device for removal of a wheel from a wheel hub, having a threaded screw connected to a retainer through a base plate, which threaded screw is engaged with the wheel hub, and a series of chains with hooks for releasably attaching the base plate to the wheel. As the treaded screw is tightened, the retainer pushes on the retainer, while the chains act to pull on the wheel rim.
While these devices have shown some utility in the field, they are primarily intended for use on trucks and heavy duty equipment in a garage environment, or they are intended for use with wheels that are hub-mounted, as opposed to being stud-mounted, on the vehicle.
Accordingly, while these prior art devices have proven to be of some use, the continued mechanic""s practice of hammering seized parts is evidence that a further improvement in wheel-pulling apparatuses would be beneficial.
Accordingly, it is a principal object of the present invention to provide a simple wheel-pulling device which can be readily used on a wide variety of vehicle types for removal of wheels, brake rotors and/or brake drums.
It is a further object of the present invention to provide a wheel-pulling device which acts to avoid exerting a pushing force directly on the axle or hub of the vehicle.
It is still a further object of the present invention to provide a wheel-pulling device which acts while avoiding a damaging rocking, or side-to-side-motion.
These and other objects are attained by providing a wheel-pulling device having a push plate which acts to push upon the mounting studs of a wheel, hook members to pull on the wheel, brake rotor or brake drum, a pull plate to which the hook members are attached, and a threaded pilot shaft which is threaded through the pull plate so that when tightened, the pilot shaft acts to push against the push plate (which in turn acts to push against the wheel studs), and pulls the hook members so as to pull the wheel rim.
Accordingly, the present invention provides a wheel-pulling apparatus comprising:
a. a push plate adapted to be placed in operative contact with a plurality of wheel studs;
b. a pull plate having two or more hook attachment points;
c. two or more hook members adapted to be attached, at a first end, to said pull plate at said hook attachment points, and which hook members are adapted to connect, at a hook end, to a wheel rim, a brake drum or a brake rotor; and
d. a threaded pilot shaft which threads through a threaded opening in said pull plate, and abuts, at a proximate end, against said push plate, and which pilot shaft has, at a distal end, a turning mechanism for turning said threaded pilot shaft within the threaded opening in said pull plate, so that said push plate exerts a pushing force on said wheel studs, and said pull plate exerts a pulling force on said wheel rim, brake drum or brake rotor, through said hook members.
Preferably, the wheel-pulling apparatus also provides a plurality of socket pins adapted to being attached to said plurality of wheel studs, wherein said socket pins are in contact with said push plate.
In a second aspect, the present invention also provides a method for the removal of a brake drum a wheel, or a brake rotor using an apparatus of the present invention as herein described.
In the context of the present specification, the phrase xe2x80x9cwheel studsxe2x80x9d is intended to mean the bolt ends which typically extend from the wheel hub on which the wheel, brake rotor, brake drum, or the like, are mounted. The xe2x80x9cwheel studsxe2x80x9d normally remain on the vehicle after the wheel has been removed. However, the phrase is also meant to include a series of bolts which might be inserted into the wheel stud openings on the hub in the situation where the actual studs are removed when the wheel is removed. The number of wheel studs can vary from vehicle to vehicle, but typically, the number of wheel studs ranges from between 3 and 8, but more typically is between 4 and 6.
In the practice of the present invention, it is preferred that the push plate exert a simultaneous pushing force against a plurality of wheel studs, and more preferably a simultaneous pushing force against all of the wheel studs (or socket pins, where used). The phrase xe2x80x9csimultaneous pushing, forcexe2x80x9d is intended to mean that the push plate generally acts on more than one wheel stud, and preferably on all wheel studs (or socket pins), as the turning mechanism is turned.
Preferably, the push plate has a central recess on one surface for receiving one end of the pilot shaft. Where the pilot shaft has a small diameter section at the end, the recess in the push plate may also be a hole through the push plate, provided that the diameter of the hole is less than the larger diameter section of the pilot shaft.
The push plate also preferably comprises a number of holes or recesses on a second surface into which the wheel studs of the socket pins can be inserted. Again, where the socket pins have a small diameter section at the end, the recess in the push plate may be a suitably sized hole. The number of holes or recesses, and sizes of the holes or recess will preferably match, or be selected based on the number and size of the wheel studs or the socket pins.
The recess in second surface of the push plate might also be a circular groove in which all of the wheel studs or socket pins will fit.
The push plate is preferably circular in shape to agree with the shape of the wheel rim, brake drum or brake rotor, although a variety of shapes might be used. Preferably the push plate is of a size to cover all of the wheel studs, but should not be significantly larger to avoid interference with the hook members unless allowances are made for the hook members to avoid interference with the push plate.
The term xe2x80x9chook membersxe2x80x9d, or xe2x80x9chooksxe2x80x9d is used in a general sense to include devices which have a traditional hook-shaped design. However, the term can also cover a series of designs, including, for example, an L-shaped design which can be used for situations where the clearance distance between parts is relatively small. Further, the term hook may also be interpreted as a device which merely contains a small xe2x80x9cshoulderxe2x80x9d area which can be used to exert a pulling force on the wheel, the wheel drum or brake rotor.
The hooks are preferably attached to the pull plate at a hook attachment point using one or more bolts at a threaded end of the hook. Preferably, between 3 and 8 hook members are used in the practice of the present invention, and more preferably, between 4 and 6 hook members are used.
A pull plate may comprise a number of hook attachment points regardless of the number of hooks being used. The number, size and location of the hook attachment points will vary depending on the size of the hooks and the configuration of the wheel rim, brake drum or brake rotor. The hook attachment points might be threaded holes into which the threaded end of the hook could be tightened, or could simply be holes through which the threaded end of the hook could be passed and then held in place by an additional bolt.
The pull plate can have a wide variety of shapes and sizes. For example, the pull plate might be circular in shape and be provided with a series of threaded holes into which the hook members might be threaded. However, in a preferred configuration, the pull plate comprises a small central portion having a threaded central hole for the pilot shaft to pass through, and a plurality of radial arms extending from the central portion, to which the hook members can be attached. The number of radial arms should preferably agree with the number of hooks to be used. Preferably the number of radial arms would be between 3 and 8 and more preferably, between 4 and 6.
In a preferred embodiment, the pull plate will have a small central portion and a plurality of radial arms each having a slot into which the threaded end of the hook member can be inserted and adjusted before being tightened into place.
The pilot shaft is of sufficient length to pass through the pull plate and abut against the push plate. The pilot shaft is threaded in the area of where it passes through the pull plate, and thus is threaded into the threaded hole in the centre of the cental portion of the pull plate.
At one end, the pilot shaft preferably has a bolt shaped head onto which a wrench or a wrench-shaped crank can be attached, and thus provides a turning mechanism for turning the pilot shaft. Alternatively, the crank can be formed as part of the pilot shaft so that no additional crank or wrench, or the like, is required.
All parts of the apparatus of the present invention are preferably made of materials which are able to withstand the forces exerted during operation. A suitable material would be, for example, steel, for most applications.